//Write a function that splits an array (first argument) into groups the length of size (second argument) and returns them as a two-dimensional array.
function arrayToGroup( arr, size ) {
  let newarray = [];
  while ( arr.length ) {
    newarray.push( arr.splice( 0, size ) )
  }
  return newarray
}
console.log( arrayToGroup( [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ], 2 ) )


//create a var newarray ie an empty array
//while loop loops until the length of arr is 0
//For each iteration splice method deletes the size number of elements and push to the newarray
//Finally newarray is returned
